1. Field of the Invention
This invention is in the field of molded leadframes and methods therefore and, more particularly, is an apparatus for handling molded leadframes and a method therefore.
2. Description of the Related Art
Apparatus for handling molded leadframes typically include at least two major functional portions, namely a gripping device and a device for moving the gripping device. The instant invention involves novel advances in at least two primary portions of a molded leadframe handling apparatus, but prior to looking at the advances provided by the instant invention, one needs to understand the state of the art, and its associated shortcomings, with respect to both the moving device and the gripping device portions.
With respect to the moving device portion, apparatus currently implement three or more drivers such as motors. In particular, one has a number of magazines, each for holding a plurality of molded leadframes. A common requirement in handling molded leadframes is the ability to pick up a molded leadframe from one of the magazines and move it over to and place it atop a different magazine. Currently, this process requires three distinct movements. First, the molded leadframe is moved vertically upward in a linear motion away from the first magazine. Then, the molded leadframe is moved linearly to a position directly above a second magazine of molded leadframes. Third, the molded leadframe is moved downward in a linear motion until it is placed and released atop the second magazine of molded leadframes. This process, which implements three distinct motions, requires a total of three separate motors or drivers of considerable expense. It would be advantageous from an economic standpoint to accomplish the desired motion of a molded leadframe with fewer motors. Additionally, this three-step motion is time inefficient. In other words, it takes a relatively long time to move the molded leadframe from one magazine to another using the three-step process. Accordingly, it would be advantageous to effect the desired movement of a molded leadframe using a more fluid and time efficient motion. Therefore, there existed a need to provide a mover portion of a molded leadframe handling apparatus which implements fewer than three motors to move molded leadframes from one magazine to another, thereby saving time and cost.
Focusing now on the current state of gripping device portions in an apparatus for handling molded leadframes, it is important to recognize that the trend in semiconductor devices today is for size to be minimized. Accordingly, the molded leadframe packages enclosing the semiconductor devices are also becoming smaller. When very small, thin molded leadframes are stacked upon each other in a magazine, the clearance between adjacent molded leadframes is extremely small. This makes it nearly impossible to insert conventional grippers between the adjacent molded leadframes in order to remove only the top leadframe from the stack. Thus, it would be advantageous to devise a gripping device portion in an apparatus for handling molded leadframes which smoothly and efficiently removes one molded leadframe at a time from a stack of molded leadframes in a magazine.
Therefore, it is the main focus of the instant invention to integrate the aforementioned advantages to the mover and gripping device portions into an improved apparatus for handling molded leadframes.